Microbiology D311 - OA Prep 2025 Guaranteed Success
What is the main difference between Gram-positive and Gram-negative bacteria?
✔️✔️ Gram-positive bacteria have a thick peptidoglycan layer in their cell wall that retains the crystal
violet stain, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane that
does not retain the stain.
Describe the process of microbial respiration.
✔️✔️ Microbial respiration is the process by which microorganisms convert organic substrates into
energy (ATP) through the oxidation of nutrients, utilizing oxygen (aerobic) or other electron acceptors
(anaerobic).
What are extremophiles and where can they be found?
✔️✔️ Extremophiles are microorganisms that thrive in extreme environments, such as high
temperatures, high salinity, acidic or alkaline conditions, and can be found in places like hot springs, salt
lakes, and deep-sea vents.
Explain the role of lysosomes in eukaryotic cells.
✔️✔️ Lysosomes are organelles in eukaryotic cells that contain enzymes to break down waste
materials, cellular debris, and pathogens, playing a key role in digestion and cellular cleanup.
What is the significance of the microbiome in human health?
✔️✔️ The microbiome consists of all the microorganisms living in and on the human body, which are
essential for digestion, immunity, protecting against pathogens, and overall health maintenance.
How do archaea differ from bacteria?
✔️✔️ Archaea have distinct genetic sequences, unique lipid membranes, and often live in extreme
environments, differing from bacteria in their biochemical and genetic makeup.
What is the function of pili in bacterial cells?
,✔️✔️ Pili are hair-like structures on bacterial surfaces that facilitate attachment to surfaces,
movement, and the exchange of genetic material during processes like conjugation.
Describe the role of the ribosome in protein synthesis.
✔️✔️ Ribosomes are molecular machines within cells that translate messenger RNA into amino acid
sequences, assembling proteins by linking amino acids together based on genetic instructions.
What is the difference between a lytic and lysogenic viral cycle?
✔️✔️ In the lytic cycle, viruses replicate and cause the host cell to lyse and release new virions, while
in the lysogenic cycle, viral DNA integrates into the host genome and replicates silently until activated.
Explain the concept of horizontal gene transfer in bacteria.
✔️✔️ Horizontal gene transfer is the movement of genetic material between bacteria through
transformation, transduction, or conjugation, allowing for genetic diversity and the spread of traits like
antibiotic resistance.
What are the characteristics of obligate intracellular parasites?
✔️✔️ Obligate intracellular parasites can only replicate inside the cells of a host organism, as they lack
the necessary machinery to reproduce independently.
How do antimicrobial peptides function in the immune system?
✔️✔️ Antimicrobial peptides are small proteins that disrupt microbial membranes, leading to the
death of pathogens and providing a first line of defense in the innate immune system.
What is the role of chitin in fungal cell walls?
✔️✔️ Chitin provides structural strength and rigidity to fungal cell walls, protecting the cell and
maintaining its shape.
Describe the process of binary fission in bacteria.
✔️✔️ Binary fission is an asexual reproduction method where a bacterial cell duplicates its DNA and
divides into two genetically identical daughter cells.
, What is the importance of the Calvin cycle in photosynthetic microorganisms?
✔️✔️ The Calvin cycle is a series of biochemical reactions that fix carbon dioxide into organic
molecules, enabling photosynthetic microorganisms to produce glucose and other carbohydrates.
How do prions cause disease?
✔️✔️ Prions are misfolded proteins that induce other normal proteins to also misfold, leading to
aggregates that disrupt cellular function and cause neurodegenerative diseases.
Explain the difference between primary and secondary metabolites in microorganisms.
✔️✔️ Primary metabolites are compounds essential for growth and reproduction, such as amino acids
and nucleotides, while secondary metabolites are not essential for growth but can provide advantages
like antibiotic properties.
What is the function of flagella in prokaryotic cells?
✔️✔️ Flagella are whip-like structures that enable prokaryotic cells to move through their
environment, aiding in processes like chemotaxis and finding nutrients.
Describe the mechanism of action of sulfonamide antibiotics.
✔️✔️ Sulfonamides inhibit the synthesis of folic acid in bacteria by blocking the enzyme
dihydropteroate synthase, which is essential for bacterial growth and replication.
What are the key features of a eukaryotic cell's nucleus?
✔️✔️ The nucleus is a membrane-bound organelle in eukaryotic cells that houses the cell's genetic
material (DNA), controls gene expression, and coordinates cellular activities like growth and
reproduction.
How do biofilms contribute to chronic infections?
✔️✔️ Biofilms protect microorganisms from the host immune system and antibiotics, allowing them
to persist on surfaces and within tissues, leading to chronic and difficult-to-treat infections.
What is the main difference between Gram-positive and Gram-negative bacteria?
✔️✔️ Gram-positive bacteria have a thick peptidoglycan layer in their cell wall that retains the crystal
violet stain, while Gram-negative bacteria have a thin peptidoglycan layer and an outer membrane that
does not retain the stain.
Describe the process of microbial respiration.
✔️✔️ Microbial respiration is the process by which microorganisms convert organic substrates into
energy (ATP) through the oxidation of nutrients, utilizing oxygen (aerobic) or other electron acceptors
(anaerobic).
What are extremophiles and where can they be found?
✔️✔️ Extremophiles are microorganisms that thrive in extreme environments, such as high
temperatures, high salinity, acidic or alkaline conditions, and can be found in places like hot springs, salt
lakes, and deep-sea vents.
Explain the role of lysosomes in eukaryotic cells.
✔️✔️ Lysosomes are organelles in eukaryotic cells that contain enzymes to break down waste
materials, cellular debris, and pathogens, playing a key role in digestion and cellular cleanup.
What is the significance of the microbiome in human health?
✔️✔️ The microbiome consists of all the microorganisms living in and on the human body, which are
essential for digestion, immunity, protecting against pathogens, and overall health maintenance.
How do archaea differ from bacteria?
✔️✔️ Archaea have distinct genetic sequences, unique lipid membranes, and often live in extreme
environments, differing from bacteria in their biochemical and genetic makeup.
What is the function of pili in bacterial cells?
,✔️✔️ Pili are hair-like structures on bacterial surfaces that facilitate attachment to surfaces,
movement, and the exchange of genetic material during processes like conjugation.
Describe the role of the ribosome in protein synthesis.
✔️✔️ Ribosomes are molecular machines within cells that translate messenger RNA into amino acid
sequences, assembling proteins by linking amino acids together based on genetic instructions.
What is the difference between a lytic and lysogenic viral cycle?
✔️✔️ In the lytic cycle, viruses replicate and cause the host cell to lyse and release new virions, while
in the lysogenic cycle, viral DNA integrates into the host genome and replicates silently until activated.
Explain the concept of horizontal gene transfer in bacteria.
✔️✔️ Horizontal gene transfer is the movement of genetic material between bacteria through
transformation, transduction, or conjugation, allowing for genetic diversity and the spread of traits like
antibiotic resistance.
What are the characteristics of obligate intracellular parasites?
✔️✔️ Obligate intracellular parasites can only replicate inside the cells of a host organism, as they lack
the necessary machinery to reproduce independently.
How do antimicrobial peptides function in the immune system?
✔️✔️ Antimicrobial peptides are small proteins that disrupt microbial membranes, leading to the
death of pathogens and providing a first line of defense in the innate immune system.
What is the role of chitin in fungal cell walls?
✔️✔️ Chitin provides structural strength and rigidity to fungal cell walls, protecting the cell and
maintaining its shape.
Describe the process of binary fission in bacteria.
✔️✔️ Binary fission is an asexual reproduction method where a bacterial cell duplicates its DNA and
divides into two genetically identical daughter cells.
, What is the importance of the Calvin cycle in photosynthetic microorganisms?
✔️✔️ The Calvin cycle is a series of biochemical reactions that fix carbon dioxide into organic
molecules, enabling photosynthetic microorganisms to produce glucose and other carbohydrates.
How do prions cause disease?
✔️✔️ Prions are misfolded proteins that induce other normal proteins to also misfold, leading to
aggregates that disrupt cellular function and cause neurodegenerative diseases.
Explain the difference between primary and secondary metabolites in microorganisms.
✔️✔️ Primary metabolites are compounds essential for growth and reproduction, such as amino acids
and nucleotides, while secondary metabolites are not essential for growth but can provide advantages
like antibiotic properties.
What is the function of flagella in prokaryotic cells?
✔️✔️ Flagella are whip-like structures that enable prokaryotic cells to move through their
environment, aiding in processes like chemotaxis and finding nutrients.
Describe the mechanism of action of sulfonamide antibiotics.
✔️✔️ Sulfonamides inhibit the synthesis of folic acid in bacteria by blocking the enzyme
dihydropteroate synthase, which is essential for bacterial growth and replication.
What are the key features of a eukaryotic cell's nucleus?
✔️✔️ The nucleus is a membrane-bound organelle in eukaryotic cells that houses the cell's genetic
material (DNA), controls gene expression, and coordinates cellular activities like growth and
reproduction.
How do biofilms contribute to chronic infections?
✔️✔️ Biofilms protect microorganisms from the host immune system and antibiotics, allowing them
to persist on surfaces and within tissues, leading to chronic and difficult-to-treat infections.
